Stone-dresser.



i. C. DODSONQ STONE DRESSER.

APPLICATION HLED sEPT.2r, 191s.

1,2402687. PatentedSpt. 18, l91?.

2 SHEETSf-SHEETI.

|NvENT`oR WITNESSES mim ATTORNEY` 1. C. DODSON.`

STONE DRESSER.

APPLICATION FILED SEPT. 21, 191s.

v PatentedSept. 18, 1917.

2 SHEETS-SHEET 2.

@im c. 222%??? JWMWQ/ M 5MM ATTOR N EY JOHN C. DODSON, OF STONE MOUNTAIN, GEORGIA."

STONE-DRESSER.

Specification of Letters Patent.

Patented sept. 1s, v1917.

Application led September 27, 1916. I Serial No. 122,463.

To all whom t may concern:

Be it4 known that I, JOHN C. DoDsoN, a citizen of the United States, residing at Stone Mountain, in the county of Dekalb and State of Georgia, have invented certain new and useful Improvements in Stone- Dressers, of which the following is a specification. f

rlhis invention has relation to an attachment for a jewelers lathe for grinding pivots, arbors, etc., and the nature and obl l jects thereof will be readily7 apparent to those skilled in the art to which it appertains, in the light of the following explanation of the accompanying drawings, illustrating what I now believe to be the preferred embodiment, or mechanical expression of my invention, from among other forms and arrangements within the spirit thereof, or the scope ofthe appended claims.

However, an object of the invention .is`

to 4provide a device adapted to be attached to a jeweler-s lathe, and embodying mechanism for imparting a reciprocatory movement to a grinding stone whereby, a pivot to be ground may be held in the head stock of the lathe, and engaged upon the abrasive element to form a conical pivot point or a shoulder pivotal point, by varying the degree of inclination of the abrasive element` by vmeans provided for that purpose.

In addition tothe foregoing my invention comprehends improvements in the details of construction, and arrangement of parts to be hereinafter more fully described, and

Fig'. 2, isa view plan of' theA lathe, .and

illustrating mygdevice in longitudinal sec-v tion, and p l Fig. 4, .is a. transverse sectional viewtaken on the linefl-4 of Fig.' V1. v v

With reference tothe drawings, 1 indicates the'bed of a jewelers lathe having ka the guide rods to the studsto which they A head stock and tail stock designated at 2 and 3 respectively, the head stock being provided with the usual pulleys 4 for rotating the chuck plate 5. In conjunction with the jewelers lathe there is provided a counter shaft` 6 disposedparallel to the bed 0f the lathe and some distance therefrom, supported in bearing brackets 7, and having belt pulleys Sand 9 iixedlysecured thereto. The belt pulley 9 is operated by means of a belt proceeding from a treadle (not shown), which may be located beneath the work bench upon which the lathe and the counter shaft are supported. Thus far the description is that of a jewelers lathe outfit at present employed.

My invention is in the way of an attachment to be applied to the bed of the lathe, and comprises a frame plate 10 which is rested upon the bed of the lathe and extended transversely thereacross and secured thereto by means of a bolt 11 which passes through apertures provided in said plate and the bed of the lathe. The frame plate l0 is provided at either end with a pair of transversely spaced studs 12 for supporting in parallelism a pair of longitudinally eX- tending guide rodsv 13, disposed in superposed relation above the frame plate 10. Nuts 14, applied to the upper threaded ends of the studs 12 serve to secure the ends of engagement thereof.

A slide 15 1s provided, having recesses 16, at either end of the slide, and at opposite edges thereof, to receive thereinV the guide rods 13, whereby the slide is'mcuntedfor` longitudinal movement in a direction transversely of the lathe bed. At one end'of the frame plate 10, a pair of upstanding transprevent disn versely spaced bearing brackets 17 are.

mounted, for supporting a transversely eX- tending crank-shaft 18 having an offset portion 19 located in longitudinaly alinement with the slide 15, said offset'portion :being connected to said slide by means of a kconnecting Vrod 20. A pinion'21 is xedly se` cured to said crank shaft, and is' designed for meshing engagement with asmaller pinion 22 mounted upon a transversely eX- tending shaft 23, which is journaled at either i endy in upstanding bearing brackets 24,

spaced transversely and supported at their Y lower ends upon a horizontal bracket arm 25v extending transversely ofthe device and having its inner end bent upward as at 26A and secured to the under side of the frame plate 10. A brace 27 may beprovided for additional support to the arm 25 and to that end is connected at one end to said arm and at the opposite end to the under side of the frame plate 10. consequently the bracket it supports, is dis-` posed parallel to the bed of the lathe and toivard the head stock, and a pulley 28is secured to the shaft 23 for rotation therewith, and in transverse alinement With the pulley 4 of the lathe, and also in alinement With the pulley 8 of the counter shaft 6 so that a belt 29 may be passed around the aforesaid pulleys 4 and -8 With its lovver stretch resting upon the pulley 28, as illustrated to advantage in Fig. 2.

lVhen the lathe is set in motion through the medium of the counter shaft after the usual fashion, the belt 29 imparts to the pulley 28 a rotative motion Which is transmitted from the shaft through the medium of the pinions 2l and 22 to the, crank shaft 1S, the rotative motion thereof being converted into reciprocatory movement of the slide 15 through the medium of the offset portion 19 and the connecting rod 20.

To proceed With a description of the supporting means for the abrasive element, 30 indi Iates afframe super-posed upon the slide 15 in parallelism thereto and in vertically spaced relation, and is formed at either end With upstanding portions 31 and 32. A hollov." post is erected centrally upon the slide l5, and is adapted to enter an opening in the plate 30, the upper end of the post being threaded to receive a nut 34 Which prevents vertical displacement of the plate 30. At either side of the post 33 a stud is extended from the slide 15 for the purpose of entering sleeves 36 depending from the under side of the plate 30, and coil springs 37 are embraced about the stud 35 and bear at either end upon the upper surface of the slide 15 With the lower end of the sleeve 86, thereby urging the plate 30 in an upward direction which movement is limited by engagement ofthe plate with the nut 34.

The end member 31 of the. plate 30 is enlarged at 3S and threaded to receive thc adjusting screw of the abrasive element. The inner end of the threaded 'rod 39 is bifurcated to form spaced extensions 40 which are secured at their terminals to a distance member 41 having a polygonal opening formed centrally therein, and set screws 42 extend radially into said discous member, with their ends projecting int-o the l aforesaid polygonal opening.' The opposite end of the threaded element 39 vis formed into a Wheel 43 ivhereby the said element may be rotated to effect the longitudinal adjustment of the stud. The abrasive ele-V ment as indicated at 44 is in the form of a relatively long bar, preferably triangular The arm 25 and in cross section, and adapted to be received at one end Within the polygonal opening formed in the chu-ck plate 41. The opposite end of the abrasive element 44 is supported in a chuck member in the form of a cylindrical member 45 Which is seated Within an opening formed in the upstanding member 32 of the plate 30, a plug 46 being slidably mounted Within the member 45 and having a polygonal opening '47 to receive the end of the abrasive element. A. spring 48 is dis-l posed Within the member 45 to urge the plug 45 in an outward direction.

To insert the abrasive element Within the supporting members therefor, one end is en gaged Within the plug t6 and the plug' moved ini'vard against the tension of the spring 48 until the opposite end of the abrasive element is'in position to be inserted in the polygonal openings of thechuck plates 41. The spring 45 urges its plug 4G and consequently the'abrasive elementV 'In a longitudinal direction, and when the end of the abrasive clement is seated within the chuck plate 4l as aforesaid, the set screws 42 are rotated unt-il rengagement from the pivot pin to be groundk is inserted, as indi- 9 cated in FigA 2, in the chuck plate 5 of the lathe, the sanie'being indicated at 49, and

the end thereofV to beI ground is rested upon t-he surface of the abrasive element 44. 1f the end of the pivot pin is to be provided with a shoulder, the upper surface of the abrasive element should be horizontal. and the length of the pivot to be ground on the pin determined by adjusting the device as a Whole longitudinally of the bed plate'of the lathe. Then the chuck plate of the lathe is set in motion through the medium of the pulleys 4 in the manner hereinbefore set forth, a reciprocatory movement is imparted to the abrasive elementi, and this motion, in addition to the rotative motion of the pivot pin 49, resultsin the formation of a shoulder pivot on the end thereof in contact With the abrasive element. During the reciprocation ofthe abrasive element spring 37 encircling the stud 35 exerts a slight up- Ward pressureV upon the abrasive element Which retains the said element in engagement with the pivot pin throughout the length of the stroke. Toprovidea conical pivot upon the end of the pivot pin, the abrasivev element 44,l may be rotated by means. of the handle `43 so as to dispose its upper surface at an angle'to the axis. of the pivot pin, whereupon a conical point will be-ground during longitudinal reciprocation' thereover may be made, and I therefore reserve the right and privilege of changing the form of the details of construction, or otherwise altering the arrangement of the correlated parts without departing Jfrom the spirit of the invention, or the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is l. The combination of a jewelers lathe adapted to receive a pivot pin in its chuck, of a pivot grinding attachment including a frame plate adapted to be secured to the lathe bed for adjustment in a longitudinal direction, a slide mounted upon the frame plate for movement in a direction transverse of the lathe bed, a frame mounted upon the slide, resilient means for urging the frame in an upward direction, chuck members at opposite ends of the frame, an abrasive element supported at either end in the chuck members and adapted to engage the pivot pin to be ground, means for imparting a reciprocatory movement to the slide, and means for actuating said slide actuating means and the lathe chuck. y

2. A pivot grinding attachment for jewelers lathes including a frame plate, a slide mounted thereon for reciprocatory movement, aframe mounted on said slide, an

abrasive element, means on one end of the frame for receiving one end of the abrasive element, a threaded member mounted in the opposite end of the frame for adjustment in a direction longitudinally of the framev and abrasive element, and means on said threaded element for engaging the other end of the abrasive element.

3. A pivot grinding attachment for jewelers lathes including a frame plate, a slide mounted thereon for reciprocatory movement, a frame mounted on said slide, a chuck member mounted on one end of the frame including a member formed with a cylindrical recess, a cylindrical block mounted in said recess for rotative and sliding movement, an abrasive element having one end mounted in said block, a spring within the recess element bearing against the block to urge the same in an outward direction, a chuck member on the other end of the frame including a threaded element mounted therein for adjustment in a direction longitudinally of t-he abrasive element, and a chuck member mounted on said threaded member` for receiving the opposite endoi:l the abrasive element.

4;. A pivot grinding attachment for jewelers lathes, including a frame plate, a slide mounted thereon for reciprocatory movement, a frame mounted on said slide, an abrasive element, means on one end of the frame for supporting one end of the abrasive element comprising a recessed member, a block mounted in said member for rotative and reciprocatory movement therein, a spring within the recessed member to urge the block outward, said block having a recess to receive one end of the abrasive element, a threaded member mounted in the opposite end of the frame for adjustment in a direction longitudinally of the abrasive element, one end of said threaded element being bifurcated, a disk member mounted within said bifurcated portion and having a recess to receive the opposite end of the abrasive element, and set screws in said disk member for securing the abrasive element against displacement.

5. A pivot grinding attachment for jewelers lathes, including a frame plate, a slide mounted thereon for reciprocatory movement, a threaded stud mounted on said slide, a frame having a central opening to receive the stud, a nut applied to said stud to secure the frame against dislodgment, sleeves mounted on the under side of the frame at opposite sides of the stud, studs on the slide adapted to enter the said sleeves, coil springs encircling the studs for urging the frame upward, an abrasive element, and means on the slide for supporting said abrasive element.

In testimony whereof I aix my signature in presenceof two witnesses.

Y JOHN C. DODSON.

Witnesses:

ALFRED BoumGNY, L. S. BOTTENFIELD.

Copies o! this patent may be obtained for ve cents each, by addressing the Commissionerof Patents, Washington, D. C. 

